The present invention relates to anti-icing apparatus for use with jet engines and the like.
It is known in aircraft that under certain atmospheric conditions, ice tends to form and build up on any part of which air impinges. This is a particular danger at the inlet of the jet engines, since such ice may obstruct the free flow of air entering the intake and as a result, it may adversely affect the operating characteristics of such engines. In the extreme, a large build-up of ice may even damage sensitive engine components due to possible break-away and collision.
For some time, anti-icing apparatus employed in aircraft for preventing the formation of ice on faired surfaces has utilized relatively warm engine bleed air and conduits for delivering this heated air under pressure to air spaces defined by apertured fairings. With the ever increasing demand for greater engine performance, the conventional engine bleed air systems are distributing air at correspondingly greater temperatures and pressures.
The increase of engine performance cannot be effectively realized unless the overall weight of the aircraft can be maintained at a minimum level. In view of the extremely high temperature and pressure, however, it has been necessary to construct the apertured fairings from material such as steel which can withstand this excessive temperature and pressure. The use of steel for the construction of engine inlet surfaces and the like, rather than lighter aluminum and aluminum alloys, has tended to increase the overall aircraft weight thus detrimentally affecting the aircraft performance.
The present invention is designed to admit controlled amounts of this heated air at the precise position where it performs its function of heating the faired surfaces sufficiently to melt the ice particles. Because the air is admitted in controlled amounts, the faired surfaces no longer need to withstand excessive temperature levels and resort can be made to advanced aerodynamic materials which provide maximum strength at a minimum amount of weight. The present invention thus permits the engine to operate at its maximum efficiency and does not add to the weight of the craft thus making the entire craft operate at maximum efficiency.